X-ray Powder Diffraction Peaks Research Articles

In-vitro cytotoxicity of biosynthesized nanoceria using Eucalyptus camaldulensis leaves extract against MCF-7 breast cancer cell line

Cerium oxide nanoparticles possess unique properties that make them promising candidates in various fields, including cancer treatment. Among the proposed synthesis methods for CNPs, biosynthesis using natural extracts, offers an eco-friendly and convenient approach for producing CNPs, particularly for biomedical applications. In this study, a novel method of biosynthesis using the aqueous extract of Eucalyptus camaldulensis leaves was used to synthesize CNPs. Scanning electron microscopy and Transmission electron microscopy (TEM) techniques revealed that the synthesized CNPs exhibit a flower-like morphology. The particle size of CNPs obtained using Powder X-ray diffraction peaks and TEM as 13.43 and 39.25 nm. Energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy confirmed the effect of biomolecules during the synthesis process and the formation of CNPs. The cytotoxicity of biosynthesized samples was evaluated using the MTT method demonstrating the potential of these samples to inhibit MCF-7 cancerous cells. The viability of the MCF-7 cell line conducted by live/dead imaging assay confirmed the MTT cytotoxicity method and indicated their potential to inhibit cancerous cells. Furthermore, the successful uptake of CNPs by MCF-7 cancer cells, as demonstrated by confocal microscopy, provides evidence that the intracellular pathway contributes to the anticancer activity of the CNPs. In general, results indicate that the biosynthesized CNPs exhibit significant cytotoxicity against the MCF-7 cancerous cell line, attributed to their high surface area.

Synthesis, characterization and antimicrobial analysis of metal-doped (Zn2+ and Ag+) brushite powder for bone regeneration

Brushite, or Dicalcium phosphate dihydrate (CaHPO4·2H2O), is a well-known calcium phosphate (CaP) found in mineralized tissues and is utilized in medical treatment, particularly in bone powder for bone repair. Brushites with Zn2+ and Ag + ions concentration were synthesized in an aqueous solution using the conventional precipitation procedure. The synthesized brushites were characterized using techniques such as Fourier Transform Infrared Spectroscopy (FTIR), Powder X-ray diffraction (PXRD), Scanning Electron Microscopy (SEM), and bioassays were carried out to evaluate their antibacterial and antifungal activities. The alterations in PXRD and FTIR peak locations demonstrated that zinc and silver ions were effectively inserted into the brushite crystals. Initial tests revealed that the powders were innocuous, which make them potentially beneficial for mineralized tissue engineering. These brushites exhibited remarkable antimicrobial activities. Zn-doped brushite completely controlled the growth of fungi namely Macrophomina phaseolina and Sclerotium rolfsii at a concentration of 0.0039 mg mL−1 while Ag-doped brushite completely arrested the growth of these fungi at 0.0312 and 0.0039 mg mL−1, respectively. Likewise, both the brushite exhibited remarkable antibacterial activity against Bacillus thuringiensis and moderate activity against Escherichia coli. Brushite compounds coupled with active metal ions, notably Ag+ and Zn2+, demonstrated promise as a distinct class of reactive materials for bone-related applications.

Tuning Pd-to-Ag Ratio to Enhance the Synergistic Activity of Fly Ash-Supported PdxAgy Bimetallic Nanoparticles.

Fly ash (FA)-supported bimetallic nanoparticles (PdxAgy/FA) with varying Pd:Ag ratios were prepared by coprecipitation of Pd and Ag involving in situ reduction of Pd(II) and Ag(I) salts in aqueous medium. All the supported nanoparticles were thoroughly characterized with the aid of powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), electron microscopy (field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM)), and elemental analyses, which include inductively coupled plasma-optical emission spectroscopy (ICP-OES) and energy-dispersive X-ray spectroscopy (EDS). A gradual broadening and shifting of PXRD peaks, ascribable to Ag, to higher angles with an increase in the Pd:Ag ratio affirms the alloying of interface between Pd and Ag nanoparticles. The coexistence of Pd and Ag was further confirmed by EDS elemental mapping as well as by the presence of bimetallic lattices on the FA surface, as evident from the high-resolution TEM analysis. The dependency of crystallite size and average size of bimetallic nanoparticles on Ag loading (mol %) was elucidated with the help of a combination of PXRD and TEM studies. Based on XPS analysis, the charge transfer phenomenon between contacting Pd-Ag sites could be evident from the shifting of 3d core electron binding energy for both Pd and Ag compared with monometallic Pd and Ag nanoparticles. Following a pseudo-first-order reaction kinetics, all the nanocatalysts were able to efficiently reduce 4-nitrophenol into 4-aminophenol in aqueous NaBH4. The superior catalytic performance of the bimetallic nanocatalysts (PdxAgy/FA) over their monometallic (Pd100/FA and Ag100/FA) analogues has been demonstrated. Moreover, the tunable synergistic effect of the bimetallic systems has been explored in detail by varying the Pd:Ag mol ratio in a systematic manner which in turn allowed us to achieve an optimum reaction rate (k = 1.050 min-1) for the nitrophenol reduction using a Pd25Ag75/FA system. Most importantly, all the bimetallic nanocatalysts explored here exhibited excellent normalized rate constants (K ≈ 6000-15,000 min-1 mmol-1) compared with other supported bimetallic Pd-Ag nanocatalysts reported in the literature.

The Magnetism of Nonstoichiometric Sr2Cr1+xRe1-xO6 (0 < x < 0.5) Double Perovskites.

The effect of nonstoichiometry on the cation distribution, crystal structure, and magnetic properties of a series of Cr-rich Sr2Cr1+xRe1-xO6 samples has been investigated. The double perovskite structure is maintained over a wide solid solution range that extends from x = 0 to approximately x = 0.5. For most of the solid solution range, the Cr-rich octahedral site maintains a nearly constant occupancy, 87% Cr and 13% Re, that is comparable to prior studies of Sr2CrReO6, while Cr steadily replaces Re on the other octahedral site. As x approaches 0.5, long-range Cr/Re ordering drops precipitously. Analysis of X-ray powder diffraction peak shapes reveals antiphase boundaries, associated with Cr/Re ordering, the concentration of which increases steadily with increasing x. Neutron powder diffraction studies confirm antiferromagnetic coupling between antisite Cr3+ ions and Cr3+ ions that occupy the normal sites, leading to site-dependent ferrimagnetic ordering. Density functional theory calculations indicate that chromium maintains a +3 oxidation state across the series, while the oxidation state of rhenium increases with increasing x. Calculations are also used to explore the energies of competing magnetic ground states. Except for the most chromium-rich compositions (x ≈ 0.5), site-dependent ferrimagnetism is retained with only a modest reduction in TC. The saturation magnetization steadily decreases as the chromium content increases due to a combination of Cr/Re antisite disorder and antiphase boundaries.

Smart Solvent-Responsive Covalent Organic Framework Membranes with Self-regulating Pore Size

Covalent organic frameworks (COFs) are an emerging class of crystalline porous materials with low density, high porosity, and excellent physicochemical stability. Recently, smart COFs with special structures and functional groups have been widely concerned, which can respond to external stimuli such as pH, temperature, light, gas, etc. However, it is still a paramount challenge to fabricate smart COF membranes possessing the advantage of alternating the pore size to realize gradient separation of multiple organic pollutants. In this work, we fabricated a 2D amine-linked smart COF membrane coupling hardness with softness via interfacial polymerization under room temperature and atmospheric pressure conditions. Interestingly, these COF membranes show higher dye rejection performance in water than in acetone, and the pore size of smart COF membranes can be dynamically regulated by different solvents. Powder X-ray diffraction (PXRD) was used to identify the intrinsic structure change of this intriguing phenomenon. By serendipity, we found that the PXRD peak shifted to a lower degree when the membranes were immersed in acetone than in water, suggesting enlargement of the pore size due to flexible frameworks. The dynamic enlargement of the pore size was reversible when the solvent was switched from acetone to water. This study not only provides a frontier of smart COF membranes but also broadens potential applications of COF materials.

Evaluating the phonon-phason coupling strength of an Al-Ni-Co decagonal quasicrystal

Recently, a novel method was proposed to probe the phonon-phason coupling effect in quasicrystals, and it was applied to an Al-Pd-Mn icosahedral quasicrystal. In this study, the method was applied to an Al-Ni-Co decagonal quasicrystal with a periodic layered structure of a two-dimensional quasicrystal. We applied elastic phonon strain along a 2-fold (aperiodic) axis in the quasicrystal plane at high temperatures with active phasons. Then, the phason strain was induced to the quasicrystal, which was demonstrated by the phason momentum (G ⊥) dependences of the powder X-ray diffraction peak widths. In contrast, when we applied phonon strain along the 10-fold periodic axis, no appreciable phason strain was observed to be induced. These results present clear evidence on the presence of phonon-phason coupling in a decagonal quasicrystal. The shape and width of the powder X-ray diffraction peaks were calculated based on the generalized elasticity of quasicrystals. The absolute value of the phonon-phason coupling constant was evaluated by quantitatively comparing the calculated results with the measured diffraction peaks.

Structural and optical analysis of YAl3(BO3)4: Pr3+ phosphors for lighting applications

A series of Pr3+ activated YAl3(BO3)4 phosphors were fabricated by solid-state reaction technique and they were characterized via phase, morphology and photoluminescence studies. Powder X-ray diffraction peaks were suitably matched to JCPDS No. 72–1978. The presence of various vibrational bonds was identified using Fourier transform infrared spectroscopy. High resolution scanning electron microscopic investigations show that the phosphor particles were distributed uniformly and presented a rod-like shape. The photoluminescence results show that the studied phosphors were easily excited by visible wavelength to produce intense-yellow to pale-yellow tunable emission. The decrease in luminescence intensity and lifetime was assigned to dipole-dipole interaction energy-transfer among excited Pr3+ ions. Observed results show that the 0.05 mol% of Pr3+ activated phosphor produce intense-yellow luminescence at 480 nm excitation.

The occurrence of monoclinic jarosite in natural environments

AbstractJarosite and related subgroup minerals are of high importance in mineral processing, as sources and sinks for metals and acidity in the environment, and they have the potential to preserve elemental and isotopic biomarkers relevant to the search for life in the solar system. The crystal structures and chemistry of jarosite minerals affect their stability and reactivity and thus the roles they play in natural and engineered systems. Rhombohedral symmetry has been documented in natural and synthetic jarosites, whereas monoclinic symmetry has only been documented in synthetic jarosites. This research reports the occurrence of monoclinic symmetry in a natural natrojarosite sample investigated using synchrotron powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), and electron backscatter diffraction (EBSD). Splitting of several rhombohedral PXRD peaks (e.g., 012, 027, and 033) into pairs of peaks was observed, with the magnitude of the splitting and the relative intensities of the pairs of peaks being almost identical to those reported for synthetic monoclinic jarosite. Rietveld refinement with room-temperature PXRD data shows an ordering of iron-site vacancies on the Fe1 site consistent with monoclinic symmetry, space group C2/m. Conversion of monoclinic unit-cell parameters into pseudo-hexagonal unit-cell parameters, specifically β′, also supports the use of a monoclinic model to describe the natrojarosite structure. Structural analysis with increasing temperature is supportive of the thermal evolution previously described for synthetic monoclinic jarosite samples, with some indications of subtle differences between synthetic and natural materials including slower rates of thermal expansion and absence of FeOHSO4 peaks for natural monoclinic jarosite. EBSD provides insight into the spatial–structural variation within the hand specimen from which the natrojarosite was sampled, demonstrating that there are areas of unambiguous monoclinic symmetry, but others where both monoclinic and rhombohedral natrojarosite coexist. The results of this study suggest that monoclinic symmetry in natural jarosites may be more prevalent than previous studies suggest. Monoclinic symmetry in jarosites is identifiable by an ordering of iron-site vacancies on the Fe1 site, splitting of specific rhombohedral XRD peaks into pairs of peaks, and an increase in jarosite symmetry (i.e., from monoclinic to rhombohedral) during heating. The splitting of peaks in monoclinic jarosites can be subtle so it is recommended that high-resolution XRD data are collected when studying the crystal structure of jarosites.

Unexpected crystallographic structure, phase transformation, and hardening behavior in the AlCoCrFeNiTi0.2 high-entropy alloy after high-dose nitrogen ion implantation

Harsh environments, such as nuclear power plants, require the development of materials with stable properties when exposed to radiation/bombardment conditions. In this work, a bulk high-entropy alloy (HEA) was implanted with nitrogen ions accelerated at 50 kV to induce and study crystal structural defects. X-ray powder diffraction (XRD) showed that the studies HEA consisted of two phases—σ and body-centered cubic (BCC)—and underwent the σ to BCC phase transformation due to ion bombardment. Unexpectedly, XRD peaks of implanted samples could not be assigned to any known simple nitride, a finding that suggests the creation of new high- or medium-entropy ceramics. Studies of the mechanical and tribological properties with the use of nanoindentation and scratch tests revealed a hardening of both phases of the implanted surface and higher wear resistance. There were also surprising increases in the hardness-to-Young’s modulus ratio and elastic recovery for both phases. The results are promising not only for the nuclear applications, but also for space applications, mechanical engineering, and tribology.

Synthesis and characterization of Barium ferrite nano-particles for X-ray/gamma radiation shielding and display applications

In the present communication, BaFe2O4 (BFO) nanoparticles were synthesized by solution combustion method using urea as a fuel and calcined at 500 °C for 3 h. To know the phase purity, functional group, surface morphology, structural analysis and energy band gap, the synthesized sample was characterized by using the techniques such as powder X-ray diffraction (PXRD), Scanning electron microscopy (SEM), Fourier transmission infrared spectroscopy (FTIR) and UV–Visible spectrophotometer. The Bragg’s reflection of PXRD confirms the formation of orthorhombic spinel crystal structure with space group Cmc21(36). In addition to orthorhombic phase, additional PXRD peaks corresponding to monoclinic phase of BFO were also observed. Wood and Tauc’s relation was used to calculate direct energy band gap and was found to be 5.2 eV. Photoluminescence studies (λex = 350 nm), CIE and CCT values revealed that the present BFO nanomaterial could meet the needs of illumination devices. In addition, X-ray/gamma ray shielding properties of BFO nanoparticles in the energy range 0.081–1.332 MeV have been measured using NaI (Tl) detector and PC based multi channel analyser (MCA). The measured shielding parameters are compared with the standard theoretical values. It is found that above 356 keV energy of gamma ray, the measured shielding parameters agrees well with the theory, whereas, slight deviation is observed below 356 keV. This deviation may be mainly attributed to the particle size of the target medium. Furthermore, an accurate theory is necessary to explain the interaction of X-ray/gamma with the nano size atoms. The present work opens new window to use this facile, economical, efficient, low temperature method to synthesize nanomaterials for X-ray/gamma ray shielding purpose as well as the display device applications.

Effects of Voigt diffraction peak profiles on the pair distribution function.

Powder diffraction and pair distribution function (PDF) analysis are well established techniques for investigation of atomic configurations in crystalline materials, and the two are related by a Fourier transformation. In diffraction experiments, structural information, such as crystallite size and microstrain, is contained within the peak profile function of the diffraction peaks. However, the effects of the PXRD (powder X-ray diffraction) peak profile function on the PDF are not fully understood. Here, all the effects from a Voigt diffraction peak profile are solved analytically, and verified experimentally through a high-quality X-ray total scattering measurement on Ni powder. The Lorentzian contribution to the microstrain broadening is found to result in Voigt-shaped PDF peaks. Furthermore, it is demonstrated that an improper description of the Voigt shape during model refinement leads to overestimation of the atomic displacement parameter.

Dosimetric applications of CdSiO3 nanoparticles prepared via Solution Combustion Technique

Pure CdSiO3 nanoparticles have been prepared by a solution combustion technique. The powders were well characterized by powder X-ray diffraction, Field Emission scanning electron microscopy and Ultra Violet-visible spectroscopy. The powder X-ray diffraction peaks of as-formed sample are broad and amorphous in nature; therefore it is further calcined at 800 oC for 2 h and its powder X-ray diffraction results shows that the sample had a good crystallization with Single phase. Debye- Scherer’s formula and Williamson–Hall plots are used to calculate the average crystallite size and found to 32-43 nm. The Scanning electron microscope and Transition electron microscope results reveal that the pure CdSiO3 nanoparticles were porous and agglomerated with irregular nanopowder. The absorption peaks for pure CdSiO3 nanoparticles were found to about 256 nm as observed in Ultra Violet-Visible spectra. The structural defects present in the material band gap (Eg) value were 5.6 eV. A well resolved thermoluminescence glow peaks in the range of (110-160) oC are observed in UV-irradiated pure CdSiO3 nanoparticles. Glow peak at 160 ºC was seen and Thermoluminescece intensity increases linearly with Ultra Violet dose in the samples. The kinetic parameters were determined by Halperin – Braner, Luschik and Chen’s methods. De-convolution of pure CdSiO3 nanoparticles exposed to Ultra Violet dose (UV dose: 30 min) was used for the estimation of kinetic parameters. Hence in pure CdSiO3 nanoparticles presence of deep traps recommends that the prepared sample may be used as a radiation dosimeter.

Sonofragmentation Synthesis of Composition-Controlled Iron-Cobalt Nanoparticles with Enhanced Magnetic Properties

Abstract Nowadays, developing simplistic, low-cost, and environment-friendly ways for the synthesis of nanoparticles (NPs) is very attractive, as reported synthesis processes with use of toxic chemicals are particularly complex. In this report, a facile and one-step approach, i.e., the sonofragmentation method, had been applied for the synthesis of FexCo1−x (x = 0.20, 0.40, and 0.80) NPs with enriched saturation magnetization and coercivity. Morphology and structure of the NPs were observed using a scanning electron microscope (SEM) and X-ray diffraction (XRD) respectively. The energy dispersive spectroscopy analysis was used for the confirmation of elemental composition. The crystalline structure of NPs was confirmed from the XRD patterns, and the crystallite size obtained from the powder XRD peak using the Scherrer equation was approximately 24.5 nm. The accumulation of NPs was observed in SEM analysis. Moreover, the magnetic property was characterized using a vibrating sample magnetometer at room temperature. The saturation magnetization (Ms) value was measured from the magnetization (M)-applied field (H) curve and found to be increased from 107 to 153 emu/g (107 to 153 Am2/kg) and the coercivity (Hc) decreased from 128 to 72 Oe (10.18 to 5.53 kA/m) for increasing the iron content in iron-cobalt NPs. Furthermore, the magnetic properties (i.e., Ms and Hc) of synthesized iron-cobalt NPs were compared with those of other methods of synthesis. The overall findings suggest that the present approach is simple, cost-effective, and environmentally safe for the synthesis of NPs.

Fabrication of LiFePO&lt;sub&gt;4&lt;/sub&gt;-Based Composite Cathode Deposited on LLTO Li-Ion Conducting Solid Electrolyte via Slurry Coating and Hot-Pressing

LiFePO4 (LFPO)-based composite cathode was deposited on Li0.35La0.55TiO3 (LLTO) solid electrolyte via slurry coating method. A composite cathode comprising of LiFePO4, LLTO, and carbon black (CB) were mixed together in a slurry and deposited on a dense LLTO pellet substrate. The effects of heat treatment temperature and hot-pressing in the structure and densification of the deposited composite cathode were investigated. Cathode component precursors were analyzed for its particle size distribution using particle size analyzer and revealed a bimodal particle size distribution for each component materials. Structural characterization using X-ray powder diffraction (XRD) analysis revealed that distinct XRD peaks were observed which can be attributed to LFPO and LLTO for the deposited as-dried and heat treated (450 °C ) composite cathodes. Surface and cross-sectional SEM images revealed that hot-pressing provided denser morphology with smaller thickness as compared to the just as-dried and heat treated samples without the application of temperature with pressure.

High magnetic coercive field in Ca‐Al‐Cr substituted strontium hexaferrite

The structural and magnetic properties of Sr0.67Ca0.33Fe9Al3−xCrxO19 submicrometric powders with substitution levels ranging from x = 0 up to x = 3, prepared by sol-gel synthesis method, have been investigated. The powders were characterized by high resolution synchrotron X-ray diffraction, scanning electron microscopy, powder neutron diffraction and MPMS-SQUID magnetometer. The structural analysis shows that upon Ca-substitution of SrFe12O19 at the Sr site and Al–Cr at the Fe sites, the magnetoplumbite structure is preserved, even for large levels of substitutions. The X-ray powder diffraction peak broadening and Williamson-Hall plots analyses indicate an increase of crystallites size and relaxation of the microstrain with increasing amounts of Chromium. The magnetic hysteresis loops reveal high coercivity fields at room temperature, with the highest value of HC = 1125 kA/m (1.41 T) obtained for Sr0.67Ca0.33Fe9Al2.5Cr0.5O19 powder interesting to develop free-Rare Earth high coercivity magnets. The saturation magnetization and remanence values increase monotonically with increasing Cr content while the switching field decreases. The structural Rietveld refinement of combined X-ray/neutron diffraction data shows the affinity of Al3+ and Cr3+ cations to migrate mainly towards (2a) Fe-Oh2 and (12k) Fe-Oh3 sites and only minor amounts is found on the (4f1) Fe-Oh1 octahedral sites. The structural observations corroborate the magnetic properties, demonstrating a correlation between the structure and magnetic properties in Ca–Al–Cr substituted strontium hexaferrite. The role of the particle size to maximize the coercivity properties is discussed.

Thermoluminescence in Eu doped NaLi2PO4TLD nanophosphor: Effect of particle size on TL characteristics

We report the thermoluminescence of Eu-doped NaLi2PO4 synthesized by solid state diffusion method. Formation of the material was confirmed by powder X-ray diffraction (PXRD) technique. Broadening of the PXRD peaks and field emission scanning microscope (FESEM) images were used for determining its particle size(s). Thermoluminescence (TL) characteristics were studied to see the effect of particle size after irradiating with γ -rays from 60Co source for wide-range (10 Gy-100 kGy) of doses. It was observed that not only TL sensitivity but also glow curve structure depends on particle size of the material. Glow curves were further deconvoluted using computerized glow curve deconvolution (CGCD) technique (after confirming the number of peaks using Tm-Tstop method) to study trapping parameters. TL glow curves mainly consist of four peaks appearing in the temperature ranges of 378–385, 426–435, 447–458 and 497–506 K. The shifts in the TL glow peak temperatures and the changes in glow curve structures can be attributed to the reorganization of local impurity levels (electron traps/luminescence centers) on widening of the band gap with reducing particle size. There can also be the effect of stress on glow curves developed due to crushing. Widening of the dose response with reducing particle size, easy method of synthesis, high sensitivity, low fading, good chemical stability, etc. make this TLD nanophosphor a good candidate for radiation dosimetry using TL.

Observation of ordered organic capping ligands on semiconducting quantum dots via powder X-ray diffraction

Powder X-ray diffraction is one of the key techniques used to characterize the inorganic structure of colloidal nanocrystals. The comparatively low scattering factor of nuclei of the organic capping ligands and their propensity to be disordered has led investigators to typically consider them effectively invisible to this technique. In this report, we demonstrate that a commonly observed powder X-ray diffraction peak around q=1.4{AA}^{-1} observed in many small, colloidal quantum dots can be assigned to well-ordered aliphatic ligands bound to and capping the nanocrystals. This conclusion differs from a variety of explanations ascribed by previous sources, the majority of which propose an excess of organic material. Additionally, we demonstrate that the observed ligand peak is a sensitive probe of ligand shell ordering. Changes as a function of ligand length, geometry, and temperature can all be readily observed by X-ray diffraction and manipulated to achieve desired outcomes for the final colloidal system.

Formulation of magnetic nanocomposites for intracellular delivery of micro-RNA for MYCN inhibition in neuroblastoma

Neuroblastoma, which accounts for almost 6% of all cancers in infants, originates from the sympathoadrenal progenitor cells within the neural crest. Approximately 25 % of neuroblastoma cases result from the amplification of the MYC-related oncogene MYCN, thus leading to high disease risk and poor prognosis; hence, studies focusing on the inhibition of MYCN are indispensable. Interestingly, microRNA-34 (miR-34) is a prospective candidate for cancer therapy because of its oncogenic and tumor-suppressing ability. This study presents the synthesis, characterization, and application of cationic magnetic nanocomposites (MNCs) comprising branched polyethylenimine (PEI)-coated iron oxide nanoparticles (IONPs). These positively charged MNCs possess the ability to penetrate the negatively charged cell wall for the delivery of miR-34a molecules into cancerous cells. The characteristic peaks at 3380, 1620, 2900, and 2840 cm−1 corresponding to −NH− and −CH2− groups suggest successful coating of PEI on the surface of IONPs. The X-ray powder diffraction (XRPD) peak of the prepared MNCs at 2θ = 35.44° resembled that of magnetite (Fe3O4, (311)). The transfection efficiency was enhanced through a magnetic field that enabled a very rapid concentration of the completely delivered vector dose onto cells. Additionally, the results of small-angle neutron scattering (SANS) revealed that core heat was generated and subsequently led to shell softening, which was activated by an alternative magnetic field (AMF). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that MNCs did not exhibit any significant toxicity against the tested cells. The increased amplification of miR-34a led to the suppression of the MYCN protein, which consequently inhibited the growth of neuroblastoma cells.

Investigation of Solid Dosage Form Components Interaction Using Orthogonal Techniques- Discovery of New Forms of Sodium Stearyl Fumarate.

Physical or chemical interactions between drug product (DP) components can occur during manufacturing and/or upon storage; and may alter DP shelf life and performance. In this work a new Powder X-ray Diffraction (PXRD) peak was observed in DP under accelerated storage conditions. Due to the complex drug product matrix (including API, polymer, fillers, super disintegrant and lubricant), it was challenging to pinpoint the component(s) responsible for the new peak. In addition to PXRD, other orthogonal techniques including Differential Scanning Calorimetry (DSC), thermogravimetric analysis (TGA), dynamic vapor sorption (DVS), Solid State Nuclear Magnetic Resonance (SSNMR) and Infrared (IR) spectroscopy were employed in this investigation to understand the root cause mechanistically. Specifically, multi nuclei SSNMR (1H, 23Na, 13C) was instrumental in delineating the components of the matrix. We identified the root cause to be an acid base reaction occurring in the DP, whereby sodium ion in sodium stearyl fumarate (SSF) is replaced by proton leading to SSF form conversion. We also identified commercially available SSF to be a hydrate that can dehydrate to an anhydrous form upon heating. In general, the same techniques can be used to investigate interactions of any multi component solid dosage forms.

Influence of Oxygen Vacancies on the Structure of BiVO4

We study oxygen vacancies in the tetragonal scheelite phase of bismuth vanadate and identify stable oxygen-deficient structures. Upon subjecting these to variable-cell optimization, we find that oxygen vacancies give rise to significant structural distortions, the degree of which exhibits a vacancy concentration dependence. Furthermore, we show that these distortions give rise to splitting of powder X-ray diffraction peaks, yielding patterns similar to that of the monoclinic scheelite phase, and that these effects are also present at finite temperatures. Our results highlight the need for characterization methods beyond X-ray diffraction for identifying the phase of synthesized bismuth vanadate samples and the importance of oxygen partial pressure control during synthesis.